1 files changed, 488 insertions, 0 deletions

diff --git a/spa/plugins/libcamera/libcamera-manager.cpp b/spa/plugins/libcamera/libcamera-manager.cpp
new file mode 100644
index 0000000..afba403
--- /dev/null
+++ b/spa/plugins/libcamera/libcamera-manager.cpp
@@ -0,0 +1,488 @@
+/* Spa libcamera manager
+ *
+ * Copyright © 2021 Wim Taymans
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <stddef.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <limits.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <utility>
+#include <mutex>
+#include <optional>
+#include <queue>
+
+#include <libcamera/camera.h>
+#include <libcamera/camera_manager.h>
+
+#include <linux/videodev2.h>
+
+using namespace libcamera;
+
+#include <spa/support/log.h>
+#include <spa/utils/type.h>
+#include <spa/utils/keys.h>
+#include <spa/utils/names.h>
+#include <spa/utils/result.h>
+#include <spa/utils/string.h>
+#include <spa/support/loop.h>
+#include <spa/support/plugin.h>
+#include <spa/monitor/device.h>
+#include <spa/monitor/utils.h>
+
+#include "libcamera.h"
+#include "libcamera-manager.hpp"
+
+#define MAX_DEVICES	64
+
+namespace {
+
+struct device {
+	uint32_t id;
+	std::shared_ptr<Camera> camera;
+};
+
+struct impl {
+	struct spa_handle handle;
+	struct spa_device device = {};
+
+	struct spa_log *log;
+	struct spa_loop_utils *loop_utils;
+
+	struct spa_hook_list hooks;
+
+	static constexpr uint64_t info_all = SPA_DEVICE_CHANGE_MASK_FLAGS | SPA_DEVICE_CHANGE_MASK_PROPS;
+	struct spa_device_info info = SPA_DEVICE_INFO_INIT();
+
+	std::shared_ptr<CameraManager> manager;
+	void addCamera(std::shared_ptr<libcamera::Camera> camera);
+	void removeCamera(std::shared_ptr<libcamera::Camera> camera);
+
+	struct device devices[MAX_DEVICES];
+	uint32_t n_devices = 0;
+
+	struct hotplug_event {
+		enum class type { add, remove } type;
+		std::shared_ptr<Camera> camera;
+	};
+
+	std::mutex hotplug_events_lock;
+	std::queue<hotplug_event> hotplug_events;
+	struct spa_source *hotplug_event_source;
+
+	impl(spa_log *log, spa_loop_utils *loop_utils, spa_source *hotplug_event_source);
+
+	~impl()
+	{
+		spa_loop_utils_destroy_source(loop_utils, hotplug_event_source);
+	}
+};
+
+}
+
+static std::weak_ptr<CameraManager> global_manager;
+
+std::shared_ptr<CameraManager> libcamera_manager_acquire(int& res)
+{
+	if (auto manager = global_manager.lock())
+		return manager;
+
+	auto manager = std::make_shared<CameraManager>();
+	if ((res = manager->start()) < 0)
+		return {};
+
+	global_manager = manager;
+
+	return manager;
+}
+static uint32_t get_free_id(struct impl *impl)
+{
+	for (std::size_t i = 0; i < MAX_DEVICES; i++)
+		if (impl->devices[i].camera == nullptr)
+			return i;
+	return 0;
+}
+
+static struct device *add_device(struct impl *impl, std::shared_ptr<Camera> camera)
+{
+	struct device *device;
+	uint32_t id;
+
+	if (impl->n_devices >= MAX_DEVICES)
+		return NULL;
+	id = get_free_id(impl);;
+	device = &impl->devices[id];
+	device->id = get_free_id(impl);;
+	device->camera = std::move(camera);
+	impl->n_devices++;
+	return device;
+}
+
+static struct device *find_device(struct impl *impl, const Camera *camera)
+{
+	uint32_t i;
+	for (i = 0; i < impl->n_devices; i++) {
+		if (impl->devices[i].camera.get() == camera)
+			return &impl->devices[i];
+	}
+	return NULL;
+}
+
+static void remove_device(struct impl *impl, struct device *device)
+{
+	uint32_t old = --impl->n_devices;
+	device->camera.reset();
+	*device = std::move(impl->devices[old]);
+	impl->devices[old].camera = nullptr;
+}
+
+static void clear_devices(struct impl *impl)
+{
+	while (impl->n_devices > 0)
+		impl->devices[--impl->n_devices].camera.reset();
+}
+
+static int emit_object_info(struct impl *impl, struct device *device)
+{
+	struct spa_device_object_info info;
+	uint32_t id = device->id;
+	struct spa_dict_item items[20];
+	struct spa_dict dict;
+	uint32_t n_items = 0;
+	char path[256];
+
+	info = SPA_DEVICE_OBJECT_INFO_INIT();
+
+	info.type = SPA_TYPE_INTERFACE_Device;
+	info.factory_name = SPA_NAME_API_LIBCAMERA_DEVICE;
+	info.change_mask = SPA_DEVICE_OBJECT_CHANGE_MASK_FLAGS |
+		SPA_DEVICE_OBJECT_CHANGE_MASK_PROPS;
+	info.flags = 0;
+
+#define ADD_ITEM(key, value) items[n_items++] = SPA_DICT_ITEM_INIT(key, value)
+	ADD_ITEM(SPA_KEY_DEVICE_ENUM_API,"libcamera.manager");
+	ADD_ITEM(SPA_KEY_DEVICE_API, "libcamera");
+	ADD_ITEM(SPA_KEY_MEDIA_CLASS, "Video/Device");
+	snprintf(path, sizeof(path), "%s", device->camera->id().c_str());
+	ADD_ITEM(SPA_KEY_API_LIBCAMERA_PATH, path);
+#undef ADD_ITEM
+
+	dict = SPA_DICT_INIT(items, n_items);
+	info.props = &dict;
+	spa_device_emit_object_info(&impl->hooks, id, &info);
+
+	return 1;
+}
+
+static void try_add_camera(struct impl *impl, std::shared_ptr<Camera> camera)
+{
+	struct device *device;
+
+	if ((device = find_device(impl, camera.get())) != NULL)
+		return;
+
+	if ((device = add_device(impl, std::move(camera))) == NULL)
+		return;
+
+	spa_log_info(impl->log, "camera added: id:%d %s", device->id,
+			device->camera->id().c_str());
+	emit_object_info(impl, device);
+}
+
+static void try_remove_camera(struct impl *impl, const Camera *camera)
+{
+	struct device *device;
+
+	if ((device = find_device(impl, camera)) == NULL)
+		return;
+
+	spa_log_info(impl->log, "camera removed: id:%d %s", device->id,
+			device->camera->id().c_str());
+	spa_device_emit_object_info(&impl->hooks, device->id, NULL);
+	remove_device(impl, device);
+}
+
+static void consume_hotplug_event(struct impl *impl, impl::hotplug_event& event)
+{
+	auto& [ type, camera ] = event;
+
+	switch (type) {
+	case impl::hotplug_event::type::add:
+		spa_log_info(impl->log, "camera appeared: %s", camera->id().c_str());
+		try_add_camera(impl, std::move(camera));
+		break;
+	case impl::hotplug_event::type::remove:
+		spa_log_info(impl->log, "camera disappeared: %s", camera->id().c_str());
+		try_remove_camera(impl, camera.get());
+		break;
+	}
+}
+
+static void on_hotplug_event(void *data, std::uint64_t)
+{
+	auto impl = static_cast<struct impl *>(data);
+
+	for (;;) {
+		std::optional<impl::hotplug_event> event;
+
+		{
+			std::unique_lock guard(impl->hotplug_events_lock);
+
+			if (!impl->hotplug_events.empty()) {
+				event = std::move(impl->hotplug_events.front());
+				impl->hotplug_events.pop();
+			}
+		}
+
+		if (!event)
+			break;
+
+		consume_hotplug_event(impl, *event);
+	}
+}
+
+void impl::addCamera(std::shared_ptr<Camera> camera)
+{
+	{
+		std::unique_lock guard(hotplug_events_lock);
+		hotplug_events.push({ hotplug_event::type::add, std::move(camera) });
+	}
+
+	spa_loop_utils_signal_event(loop_utils, hotplug_event_source);
+}
+
+void impl::removeCamera(std::shared_ptr<Camera> camera)
+{
+	{
+		std::unique_lock guard(hotplug_events_lock);
+		hotplug_events.push({ hotplug_event::type::remove, std::move(camera) });
+	}
+
+	spa_loop_utils_signal_event(loop_utils, hotplug_event_source);
+}
+
+static void start_monitor(struct impl *impl)
+{
+	impl->manager->cameraAdded.connect(impl, &impl::addCamera);
+	impl->manager->cameraRemoved.connect(impl, &impl::removeCamera);
+}
+
+static int stop_monitor(struct impl *impl)
+{
+	if (impl->manager) {
+		impl->manager->cameraAdded.disconnect(impl, &impl::addCamera);
+		impl->manager->cameraRemoved.disconnect(impl, &impl::removeCamera);
+	}
+	clear_devices (impl);
+	return 0;
+}
+
+static void collect_existing_devices(struct impl *impl)
+{
+	auto cameras = impl->manager->cameras();
+
+	for (std::shared_ptr<Camera>& camera : cameras)
+		try_add_camera(impl, std::move(camera));
+}
+
+static const struct spa_dict_item device_info_items[] = {
+	{ SPA_KEY_DEVICE_API, "libcamera" },
+	{ SPA_KEY_DEVICE_NICK, "libcamera-manager" },
+};
+
+static void emit_device_info(struct impl *impl, bool full)
+{
+	uint64_t old = full ? impl->info.change_mask : 0;
+	if (full)
+		impl->info.change_mask = impl->info_all;
+	if (impl->info.change_mask) {
+		struct spa_dict dict;
+		dict = SPA_DICT_INIT_ARRAY(device_info_items);
+		impl->info.props = &dict;
+		spa_device_emit_info(&impl->hooks, &impl->info);
+		impl->info.change_mask = old;
+	}
+}
+
+static void impl_hook_removed(struct spa_hook *hook)
+{
+	struct impl *impl = (struct impl*)hook->priv;
+	if (spa_hook_list_is_empty(&impl->hooks)) {
+		stop_monitor(impl);
+		impl->manager.reset();
+	}
+}
+
+static int
+impl_device_add_listener(void *object, struct spa_hook *listener,
+		const struct spa_device_events *events, void *data)
+{
+	int res;
+	struct impl *impl = (struct impl*) object;
+	struct spa_hook_list save;
+	bool had_manager = !!impl->manager;
+
+	spa_return_val_if_fail(impl != NULL, -EINVAL);
+	spa_return_val_if_fail(events != NULL, -EINVAL);
+
+	if (!impl->manager && !(impl->manager = libcamera_manager_acquire(res)))
+		return res;
+
+	spa_hook_list_isolate(&impl->hooks, &save, listener, events, data);
+
+	emit_device_info(impl, true);
+
+	if (had_manager) {
+		for (std::size_t i = 0; i < impl->n_devices; i++)
+			emit_object_info(impl, &impl->devices[i]);
+	}
+	else {
+		collect_existing_devices(impl);
+		start_monitor(impl);
+	}
+
+	spa_hook_list_join(&impl->hooks, &save);
+
+	listener->removed = impl_hook_removed;
+	listener->priv = impl;
+
+	return 0;
+}
+
+static const struct spa_device_methods impl_device = {
+	SPA_VERSION_DEVICE_METHODS,
+	.add_listener = impl_device_add_listener,
+};
+
+static int impl_get_interface(struct spa_handle *handle, const char *type, void **interface)
+{
+	struct impl *impl;
+
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+	spa_return_val_if_fail(interface != NULL, -EINVAL);
+
+	impl = (struct impl *) handle;
+
+	if (spa_streq(type, SPA_TYPE_INTERFACE_Device))
+		*interface = &impl->device;
+	else
+		return -ENOENT;
+
+	return 0;
+}
+
+static int impl_clear(struct spa_handle *handle)
+{
+	auto impl = reinterpret_cast<struct impl *>(handle);
+
+	stop_monitor(impl);
+	std::destroy_at(impl);
+
+	return 0;
+}
+
+impl::impl(spa_log *log, spa_loop_utils *loop_utils, spa_source *hotplug_event_source)
+	: handle({ SPA_VERSION_HANDLE, impl_get_interface, impl_clear }),
+	  log(log),
+	  loop_utils(loop_utils),
+	  hotplug_event_source(hotplug_event_source)
+{
+	libcamera_log_topic_init(log);
+
+	spa_hook_list_init(&hooks);
+
+	device.iface = SPA_INTERFACE_INIT(
+			SPA_TYPE_INTERFACE_Device,
+			SPA_VERSION_DEVICE,
+			&impl_device, this);
+}
+
+static size_t
+impl_get_size(const struct spa_handle_factory *factory,
+	      const struct spa_dict *params)
+{
+	return sizeof(struct impl);
+}
+
+static int
+impl_init(const struct spa_handle_factory *factory,
+	  struct spa_handle *handle,
+	  const struct spa_dict *info,
+	  const struct spa_support *support,
+	  uint32_t n_support)
+{
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(handle != NULL, -EINVAL);
+
+	auto log = static_cast<spa_log *>(spa_support_find(support, n_support, SPA_TYPE_INTERFACE_Log));
+
+	auto loop_utils = static_cast<spa_loop_utils *>(spa_support_find(support, n_support, SPA_TYPE_INTERFACE_LoopUtils));
+	if (!loop_utils) {
+		spa_log_error(log, "a " SPA_TYPE_INTERFACE_LoopUtils " is needed");
+		return -EINVAL;
+	}
+
+	auto hotplug_event_source = spa_loop_utils_add_event(loop_utils, on_hotplug_event, handle);
+	if (!hotplug_event_source) {
+		int res = -errno;
+		spa_log_error(log, "failed to create hotplug event: %m");
+		return res;
+	}
+
+	new (handle) impl(log, loop_utils, hotplug_event_source);
+
+	return 0;
+}
+
+static const struct spa_interface_info impl_interfaces[] = {
+	{SPA_TYPE_INTERFACE_Device,},
+};
+
+static int
+impl_enum_interface_info(const struct spa_handle_factory *factory,
+			 const struct spa_interface_info **info,
+			 uint32_t *index)
+{
+	spa_return_val_if_fail(factory != NULL, -EINVAL);
+	spa_return_val_if_fail(info != NULL, -EINVAL);
+	spa_return_val_if_fail(index != NULL, -EINVAL);
+
+	if (*index >= SPA_N_ELEMENTS(impl_interfaces))
+		return 0;
+
+	*info = &impl_interfaces[(*index)++];
+	return 1;
+}
+
+extern "C" {
+const struct spa_handle_factory spa_libcamera_manager_factory = {
+	SPA_VERSION_HANDLE_FACTORY,
+	SPA_NAME_API_LIBCAMERA_ENUM_MANAGER,
+	NULL,
+	impl_get_size,
+	impl_init,
+	impl_enum_interface_info,
+};
+}